Setts



A. L. RUSSELL AND C. E. GRUSH. UPPER STRETCHING MACHINE. APPLICATION FILED JULY 11. IBIS. RENEWED JULY 5. [91s.

1,313,91 8. Patented Aug. 26,1919.

@ flag UNITED STATES PATENT OFFICE.

ARTHUR L. RUSSELL, OEBOSTON, AND CHARLES E. GRUSH, OF BEVERLY, MASSACHU- SETTS, ASSIGNORS, BY MESNE ASSIGNMENTS, TO UNITED SHOE MACHINERY COR- PORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

UPPER-STRETCHING MACHINE.

Specification of Letters Patent.

Patented Aug. 26, 1919.

Application filed July 17, 1916, Serial No. 109,664. Renewed July 6, 1918. Serial No. 243,708.

To all whom it may concern:

Be it known that we, ARTHUR L. RUSSELL and CtuAnLns E. GRUsrI, citizens of the United States, residing at Boston, in the county of Suffolk, State of Massachusetts, and at Beverly, in the county of Essex and State of Massachusetts, respectively, have inventedcertain Improvements in Upper- Stretching Machines, of which the following descrlption, in connection with the accompanying drawings, in a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to machines for stretching leather and in particular to machines for operating upon upper leather for use in boots and shoes to efiect improvements in fit, facilitate the lasting operation, and reduce the cost of manufacture.

The invention embodies certain improvements in the machine for applying local stretching to the interior portions of stock progressively, by repeated operations of the machine, disclosed in our eo-pending application Ser. No. 827,609, filed March 27, 1914:, and has for one of its objects to simplify the mechanism while retaining important advantages of that machine. The present invention contemplates the employment of mechanism for subjecting a small area only of the stock to tension at a time, and at the next operation subjecting the same, or an adjacent area, to tension during the continuous running of thevmachine, so that interior portions of the upper may be permanently stretched and thus be made to fit the high and low port-ions of lasts, and to truly conform to the varying curvature of their surfaces.

, The local stretching of the stock is preferably performed by two pincers whose jaws are spaced apart an appropriate distance and are adapted to seize adjacent portions of stock, to move apart for stretching the stock,-and to then retract, and also to separate and release the stock. These operations may be repeated as many times as desired, either at the same point or at different points on the sheet.

Conveniently, and as herein shown, the pincers consist of two jaws pivotally connected with links which are joined by a common pivot to a reciprocatory plunger located on one s de o a Work table, and twq cooperating jaws which extend through an opening in the table and are supported by links pivotally sustained from a rigid extension of the table and located on the opposite side of the latter. The links for sustaining the first-mentioned jaws have ends extending beyond their pivots which are spring-pressed to hold the jaws normally apart a desired distance, and the cooperating jaws are maintained, yieldingly. and adjustably, in proper relation to the first-named jaws. When the plunger is depressed the adjacent pincers will first seize the stock and then be caused to moved apart to stretch the stock; and when the plunger is moved reversely the pincers will first approach each other, and the jaws of each pincer will then separate to release the stock. The described operations may be repeated, as many times as desired, upon the same, or adjacent portions of the stock, until the latter has been stretched at the places, and to the extent required, to fit properly the high and low portions of a last, or the varying curvatures of a last or any other irregularly shaped form. Preferably the plunger which supports and actuates the first-mentioned pincer jaws is reciprocated by a cam having a path so designed as to impart a slow pulling movement to the pincers through about one-half the cycle to seize and stretch the stock, then a dwell during onefourth of the cycle to hold the stock under tension so as to render the stretching permanent, and a quick return for the remaining one-fourth of the cycle to lift the jaws from thestock rapidly and thus lessen the inward drag of the jaws on the stock.

The several features of invention embodied in the illustrated mechanism, including important details of construction and combinations of parts, will be hereinafter more particularly described and will be pointed out in the claims.

In the drawings:

The figure shows, in side elevation, partly sectional, a machine embodying the present invention.

The machine frame 1 has a base 3 which supports the internally threaded hub 9 of a hand wheel 7 the hub 9 being formed with an external groove 10 which receives a lug 13 projecting from a plate which is clamped to the ba A Work table has base 11 base 11.

which is rigid with a screw stem 5 having a coarse thread, and fitting the internal thread of the hub 9. The stem 5 has a vertical slot 50 which receives a guide pin 6, projecting rigidly from the frame base, said parts serving to prevent rotation of the screw stein.- By turning the hand wheel the screw stem will be caused to feed up or down, according to the direction of rotation, and the work table may thus be adjusted to locate its work-receiving surface in the desired relation to the plane of the pincer jaw. During the rotation of the hand wheel the engagement of the lug 13 with the groove 10 will retain the hand wheel against vertical movement and thereafter will hold it adj usted.

The upper part of the machine frame supports suitable bearings for a shaft carrying a; pulley 14 which may receive power, through a belt, from a suitable source. The pulley shaft carries a disk having a crank pin 16 thereon which runs in a cam groove 18, in a cam block 19,. The cam block operates a plunger which is guided for reciprocating movements by a plate 24, bolted to the frame, and by a stem 20, rigid with the upper part of the cam block, and guided suitably by a plate 21 which is likewise bolted to the frame. There is a yielding lost motion connection between the stem and plunger, as shown in the drawings, and the plunger 22 sustains, by a pivot 26, the two jaw-supporting links or arms 28', 28, which respectively sustain, through pivots, each of the uppermost pincer jaws 32, 3 2, whose lower faces have sufficient friction quality to maintain engagement with the stock. The links 28 have divergently extending upper end portions 29 normally acted upon by a spring 30 which holds the jaws normally pressed toward each other and against the stop 33' and thereby maintains the jaws 32,, 32'spaced a suitable distance from each other, and leaf springs 34, 34 are secured to the arms 28, 28 and bear at their free ends against the jaws 3'2, 32 so as to hold them yieldingly with their faces in substantial parallelism with the faces of the other pincer jaws 36, 36.

The jaws 36, 36 which, if. they are to en gage the inner side of'the leather stock, preferably have their faces roughened slightly to prevent slipping, project through an opening 37 in the work table 12, and are supported by links 38, 38 whose lower ends are sustained by a single pivot 40' from the table al-ined horizontal perforations through which! passes an adjusting rod 42, having at its outer free end a knurled or roughenedhandle 43. The rod is encircled. by a spring'41 that holds jaws 36, 36 normally apart and the rod has right and left hand external screw threads engaging internal screw threads in The links 38 are provided with two spaced nuts 44, 44 which are provided with pins 48, 48, moving in guiding slots formed in two sleeves 46, 46. These sleeves are bored to receive the nuts 44 and are also formed at their inner ends with forked portions which embrace the links 38. Spiral springs 49 are located in the bores of the sleeves between the inner ends of the nuts and the bottoms of said bores and hold the jaws normally in the position shown until the stock has been gripped between the upper and the lower aws. Then the springs yield to allow the jaws to' separate to stretch the stock. The springs 49 return the jaws to their initial position after each stretchingoperation.

By turning the handle 43 the tension of the springs may be adjusted to insure different degrees of grip-ping force before the p-incers begin to separate to stretch the stock. 7

The cam groove 18 is formed with a substantially flat, or horizontal portion l8 along which the crank pin? 16 acts during about one-half of the cycle, which movestaining the stock stretched for an intervalv of time which tends to' render the stretching permanent. Thereafter the crank pin reaches the end of the curved portion 18 of the groove, and for the remaining onequarter of its stroke the crank pin acts to quickly raise the plunger 22, thus causing a rapid release of the stock from the gripping action of the pincers, This'is especially advantageous in that it tends to prevent any drag of the pincer jaws over the stock during the inward movement of the jaws, as they are lifted instantly from the work.

This machine is well adapted for stretching different portions of stock interiorly of the edges thereof, and especially those parts of a shoe upper which are fitted to the high and low portions of a last, and by the machine toe caps or the tip portions of shoe uppers may beistretched to conform truly to the convexity or concavity of a last so that the parts may be cut somewhat smaller than at present, and may be made to fit the toe of the last with less manipulation in the relation to the gripping faces of the jaws 32, 32, the extent to which the pincers move apart for stretching the stock being determined by the elevation of the lower jaws and the table because the stroke of the cam and therefore of the upper jaws is constant. The hand wheel 43 is also turned, to the right or to the left, effecting an inward or outward movement of the jaws 36 to properly aline them with the jaws 32.

In the use of the machine a piece of leather stock is placed upon the work table with the portion which is to be stretched located between the pincer jaws. Power be ing then applied, through a belt or other suitable means, to the pulley 1a and the crank pin being at its highest point, said crank pin first causes a depression of the plunger carrying the jaws 32, 32, the stock being gripped between these and the cooperating jaws, and further movement of the vplunger effects a separation of the pincers to stretch the stock, with a suitable dwell at the end of the stretching movement, and thereafter a lifting of the pincer jaws 32 to release the stock. If the machine continues to operate while the stock remains in one position the same area may be subjected to a plurality of successive tensioning operations, until the desired amount of stretching has been attained. The operator may then move the stock to a different position and subject a different area to as many successive tensioning impulses of the machine as may be desired. The upper may not only be stretched along parallel lines back and forth by feeding the stock properly by hand during the intervals between the pulling movements of the pincers, but the work may be turned so as to obtain successive stretching effects in different directions, as when shaping a toe cap to fit over the toe end of a last. In shaping an upper to fit the last back of a high toe to prevent bridging from the toe to the instep a stretching in a direction lengthwise of the last only is required to provide an amount of fullness sufficient to ermit the upper to lay into the hollow of the last. Similarly in shaping shank portions of a shoe. upper where it is desired to make the leather fit a narrow shank last the direction of stretching will be mainly lengthwise and may be made greater at the edge of the stock and gradually diminishing at a point remote from the edge. This gradation of the stretching action is obtainable by feeding the stock along by hand at the proper 'ate during the continuous operation of the machine, the rate of feed being increased as the operation progresses farther from the edge of the stock. a J

In the stretching and retracting movements of the pincers the links 28, 38 for the two pincers constitute in effect two toggle joints, having movements in opposite direc tions,- toward and from each other. The fact that a pin 26 pivot-ally supports one link of each toggle, while a pin 40 pivotally supports the other link of each toggle, and that said pins are located in line with the center of the reciprocating plunger 22 insures uniformity of movement of the jaws of the pincers as they move apart to stretch the stock, and move reversely to release the stock. This constitutes a very simple and ctlicient mechanical construction for operating the stretching pincers, and we regard it as a very important feature of the present invention. Use of a table, while convenient, is not necessary and the operating plunger may be connected with the lower pair of toggle members instead of the upper pair if desired. It is contemplated that the stock stretching movements shall be comparatively short and that the machine shall usually be run at a speed permitting the stock to recover itself more or less, or react partially or completely as its elasticity will cause it to do, between successive stretching actions on the same portion of the stock to avoid a cumulative effect liable to produce rupture of the stock.

The work engaging faces of the jaws are preferably of large area compared with the space between the jaws so that there is a very substantial compressing or beating of the stock effected by the jaws, as the stock is moved progressively between them, in addition to the stretching of the stock. This organization will distend stock materially without opening the grain of the stock to any marked degree.

Having described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A machine of the class described having, in combination, a work support, pincers arranged for engaging an interior portion of stock, and mechanism to cause said pincers to seize the stock, to move relatively for stretching it, to cease the stretching movement and hold the stock under tension, and to release the stock.

2. A machine of the class described having, in combination, a work support, pincers ar'angcd for engaging interior portlons of stock on said work support, and actuating means for the pincers to cause them to seize the stock, to move apart for stretching it, to cease the stretching movement and hold the stock under tension, and to release the stock.

3. In a machine of the class described, the combination with a work support, of pincers for engaging stock at separated points located within and removed froln the edges of the stock, means for imparting positive movements to the pincers to seize the stock and stretch it, and yielding means to cause the pincers to release the stock and return to initial position,

4. In a machine of the class described, the combination with a work support, of pincers for engaging stock on said support, toggle members for supporting a jaw of each pincer on each side of said support, and actuating means for the toggles to cause the pincers to seize, stretch and release the stock.

5. In a machine of the class described, the combination with a work support, of pincers for engaging stock on said support, toggle members supporting a jaw of each pincer on one side of the stock, toggle members supporting another jaw of each pincer on the opposite side of the stock, and actuating means for the toggles to cause the jaws to seize stock, to move apart to stretch it, and to move reversely to release it.

6. In a machine of the class described, the combination with a work support, of toggle members sustaining two pincer jaws on. one side of said support, toggle members connected with two cooperating pincer jaws on the opposite side of said support, and a reciprocating member having pivotal connection with said last-named toggle members and arranged for actuating the toggles to cause the pincers to seize and stretch the stock. 7

7. In a machine of the class described, the combination with a work support, of pincers arranged to engage interior portions of stock on the support, toggles having connection with the pincers jaws on opposite sides of said support, and actuating means for the toggles to cause the pincers to seize, stretch and release the stock.

8. In a machine of the class described, the combination with a work support, of pincers having jaws arranged to engage the two opposite sides of stock at spaced points within its edges, toggle members sustained from a common pivot and carrying the pincer jaws for operating on one side of the stock, other toggle members sustained from a single pivot and carrying the pincer jaws for operation on the opposite side of the stock,- and actuating means for the toggles to cause the pincerscto seize and stretch stock.

9. In a machine of the class described, the combination with a work support, of pincers for seizing and stretching stock thereon and comprising jaws sustainedabove and .below said support, means for adjusting saidsupport relative to the plane of the upper jaws,- and actuating means forthe pincers.

10. Ina machine of the class described, the combination with a work support, of pincers for seizing and stretching stock thereon and comprising jaws sustained above said support, cooperatlng jaws carried by the work support, and means for adjusting said jaws and work support with relation to the plane of the faces of the first-mentioned jaws. j H i.

11. In a machine of the class described,

the combination with a work support, of pincers having jaws arranged to engage opposite sides of stock at spaced points, actuating means to cause the pincers to seize and stretch the stock, and means for adjusting the jaws on one side of the stock relatively to the jaws on the opposite side of the stock in a plane parallel with the stock-engaging faces of the jaws.

12. In a machine of the class described, the combination with a work support, of pincers having jaws arranged to engage opposite sides of stock at spaced points, actuat ing means to cause the pincers to seize and stretch the stock, and means for adjusting the jaws on one side of the stock relatively to the jaws on the opposite side of the stock in planes parallel with and perpendicular to the stock-engaging faces of the jaws.

13. In a machine of the class described,- the combination with a work support, of

pincers having jaws for engaging stock at.

spaced points thereon, adjusting means to move the jaws on one side of the stock toward or from each other in the plane of the stock-engaging faces of said jaws, and actuating means to cause the pincers to seize and stretch the'stock.

14. In a machine of the class described, the combination with a work support, of pincers having jaws for engaging stock thereon, pivotal means to support the jaws on one side of the stock, an adjusting rod, and yielding means between said rod and jaws for effecting movements of said jaws in opposite directions in a plane parallel with the stock-engaging faces of the jaws.

15. In a machine of the class described, the combination with a work support, of pincers having jaws for engaging stock thereon, links supporting the pincer jaws on one side of the stock, and adjusting devices for said jaws comprising a rod having right and left hand threads thereon, nuts engaging said threads, sleeves engaging opposite sides of said links,- and springs located between said nuts and sleeves.

16. In a machine of the class described, the combination with a work support, of pincers having jaws arranged to engage op posite sides of stock, and actuating means for the pincers, including toggles arranged to cause the pincers to seize the stock, to move apart and stretch it, and to move re versely and release it. I, k g

I 17. In a machine of the class described, the combination with a work support, of pincers havingnjaws arranged to engage opposite 7 sides .of, stock, toggle members for supporting thej aws on one side, of the stock, pivotal means connecting said jaws and toggle members, and yielding means to maintain the stockengaging, faces of said jaws in proper relation with the plane of the stock.-

18. In a machine of the class described, the combination with a work support, of pincers for seizing and engaging stock, togle members supporting cooperating pincer aws on opposite sides of said support, a plunger pivotally connected with the toggle members above the support, a cam connected with said plunger and having a path designed to impart first a slow movement to the toggles for causing the pincers to seize the stock and move apart to stretch it, then I a dwell to hold the stock under tension, and

finally a quick movement to release the stock, a crank =pin moving in said path, and actuating means for said crank pin.

19. A machine of the class described having, in combination, a pair of spaced pincers having jaws for engaging stock, pivotal means for supporting the jaws upon one side of the stock, a plunger having pivotal connection with the jaws upon the opposite side of the stock, and means for reciprocating said plunger to cause said pincers to engage the stock, to spread apart for stretching it, and to move reversely for releasin the stock.

20. n a machine of the class described, two reversely flexed pairs of toggles the members of which are disconnected at their knuckles and provided with gripping faces, and means for relatively moving the upper members of the toggles toward the lower members to effect gripping of stock between the upper and lolwer members and then stretching of the stock between the respective grippers by further flexing of the toggles.

21. In a machine of the class described, two reversely flexed pairs of toggles the members of which are disconnected at their knuckles and provided with gripping faces, and means for relatively moving the upper members of the toggles toward the lower members to effect grip-ping of stock between the upper and lower members and then stretching of the stock between the respective grippers by further flexing of the toggles, combined with means to hold the toggles in initially flexed relation until the stock has been gripped and then to yield to allow the additional flexing for stretching.

2:2. A machine of the class described having, in combination, spaced pairs of pincer jaws for engaging the opposite sides of stock, and continuously operating means to cause said jaws to seize the stock, to move apart to stretch it, to then dwell and hold the stock under tension, and to move reversely to release the stock.

23. A machine of the class described having, in combination, spaced pairs of pincer jaws for engaging the opposite sides of stock, toggles supporting said jaws, and continuously operating means to cause the jaws to engage the stock, to move apart to stretch it, and to release the stock.

24. A machine of the class described, having, in combination, members arranged for engaging an interior ortion of the stock, and power-driven mec anism to cause said engaging members to separate relatively and successively for stretching the stock and to cease the stretching movements and dwell for a time determined by the mechanism, to hold the stock under tension, thereby producing a permanent fullness over definite interlor areas.

25. A machine of the class described having, in combination, members arranged for engaging the stock over an area confined to portions removed from the edges, and mechanism to cause said engaging members to separate relatively for stretching the stock, to cease the stretching movement and hold the stock under tension, and to approach relatively at a different rate from the movement of separation to relax the tension upon the stock.

In testimony whereof we have signed our names to this specification.

ARTHUR L. RUSSELL. CHARLES E. GRUSH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

